On Fri, Jun 05, 2015 at 02:16:40PM +0200, Heiko Stübner wrote: > Hi Thierry > > Am Freitag, 5. Juni 2015, 13:02:01 schrieb Thierry Reding: > > If this is specific to the Rockchip implementation, shouldn't this go > > into Documentation/devicetree/bindings/video/dw_hdmi-rockchip.txt? It > > could then simply go into the Rockchip DRM tree. > > actually, we determined that the supply names are universal to the IP > (both in imx and rockchip and probably more if there are more users > out there). Just Russell requested that we don't pollute the generic > code until necessary, as it looks like the supply of those is somehow > handled internally on the imx. Why do you think it's universal? Let's start from the beginning, before we create something that's not representative of the hardware. dw_hdmi actually drives two pieces of hardware - the HDMI transmitter, and a separate hardware block, the HDMI phy. There are at least two possible HDMI phys referenced in the iMX documentation - there is one called HEAC which doesn't appear in iMX devices afaik, and the one which does, which is a 3D phy. The 3D phy top level IO diagram does have VPH and VP power supplies, but it also has VP_FILT0, VP_FILT1, VP_FILT2, VP_FILT3 and GD labelled up as "Power supply signals". Where they connect to in the rest of the system - or whether they are connected - is undocumented. The HDMI transmitter itself is not documented what it's supplies actually are. So, what we currently have in DT for dw_hdmi is something which doesn't _quite_ reflect the hardware right now, and to go adding VP and VPH supplies to the generic binding is wrong - it doesn't follow the hardware structure detailed in the iMX documentation I have. As the Rockchip documentation is not available, I can't comment whether it would be current proposal is appropriate for Rockchip or not, which is why I haven't commented on this other than saying that it's not appropriate to be a generic dw_hdmi binding. If we wanted to model this correctly, then for iMX, I would suggest that the HDMI phy should be modelled in DT, and _all_ the six VP* supplies are modelled - and we should assume that "GD" is a "power good" signal, though we don't know that for certain. What we also don't know on iMX6 is what voltages any of these are supplied with. So, as we don't have much certainty here, and we know that adding it to what is the HDMI transmitter would be wrong, I'd suggest not modelling it in a generic way at present. -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
